Injection moulding, extrusion, vacuum or pressure deformation and rotation moulding are the most common processes for plastics or thermoplastics. Unwanted metallic parts in plastics may cause clogging of the nozzle or spray openings.
Minimal nozzle thickening completely distorts the dosing of the plastic, which in the worst case scenario will result in the rejection of a whole batch of products.
In addition, in the case of a blockage, the manufacturer needs to dismantle and clean the blocked nozzle or - in the worst case scenario – replace it in its entirety. This means a few hours or longer of production downtime.
In some cases, contamination does not result in a blockage of the injectors, but slips in between the pump and nozzle, and finally ends up in the finished product.
The contaminated batch is placed in quarantine for further investigation. This helps determine the cause which prevents future occurrences. In addition to the additional costs of the investigation, it may also result in a product or even entire batch being rejected.